public class VariableTest {
    public static void main(String[] args) {
        //年龄变量
        int age = 18;//声明和初始化
        age = 19;//修改变量的值

//        age = 20.5;

        double score = 80;
        //byte<short<int<long<float<double
        //     char
    }

    public static void show(){
//        System.out.println(age);
    }
}
